ACL Injury: Who's At More Risk?

There are athletes that are more subject to an ACL injury than the others. Gender, sports they participate in, muscle balance/strength, biomechanics, etc. Some risk factors can be fixed/eliminated, but some may not. Injuries cannot always be avoided, however, it is a lot easier to prevent it than to rehabilitate after surgery.

Female

Female athletes are shown to be 4-6 time more at risk of ACL injuries than male counterparts. This may not sound fair but it is the fact that just being female increases the risk.

Sports

Certain sports have a higher injury rate than others. Those high risk sports include soccer, gymnastics, basketball, football, skiing, etc. ACL injuries can also happen in other sports such as tennis, baseball, and softball, but not as common as in sports listed above.

Previous Injury

Athletes who have had an ACL injury previously may be prone to re-injuring the same or the opposite knee. Some research articles deny it, on the other hand, there are research articles that have proven this is the fact.

Muscle Imbalance

Athletes who have side-to-side muscle imbalance may be more at risk. These athletes have one leg that is stronger than the other. Also, muscle imbalance can occur between two muscle groups (quadriceps and hamstrings). Usually, the quads are stronger than the hamstrings. But if hamstring strength drops below a certain percentage of quad strength, the athlete may be at a higher risk of injury.

Core Strength/Proprioception

Decreased core strength and proprioception have been linked to lower leg injuries. Core strength and proprioception play an important role in postural control and inability to control posture during athletic activities well will put the athletes at risk of injuries.

Biomechanics

There have been numerous research articles that studied biomechanical differences during landing and athletic activities. Athletes with biomechanical deficit are the ones whose knees bend inwardly during landing. This tends to happen more in female athletes. Female athletes also tend to keep their knees straighter compared to male athletes, which is also considered to be a risk factor. As a result, these athletes may not be able to absorb a GRF (ground reaction force) and their knee may be sustaining higher GRF.

Maturation

After growth spur, body weight and height increase drastically. As peak growth occurs, their muscle strength needs to increase in order to support increased body weight. Male athletes seem to successfully be able to get stronger as they grow, however, this adjustment does not seem to happen to females, leading to a gender difference in muscle strength after growth spur. This may be linked to a higher injury rate in female athletes after puberty.


There may be other risk factors. Athletes who participate in high risk sports should be participating in a prevention program as well as those who are considered to be at a higher risk of injury.